It has long been believed that stuttering is associated with poor mental health. At one time it was thought that an anxious temperament was a cause of stuttering, but more recent evidence suggests that anxiety and other mental health difficulties are a result rather than a cause of stuttering; for example, children who stutter often experience negative attitudes and even bullying from other people, and such experiences can lead to mental health problems such as anxiety and poor self-esteem. Few studies have used community samples to look at the association between stuttering and mental health problems. ALSPAC is a particularly appropriate resource for exploring such questions, because unlike other similar studies, speech and language therapists checked for stuttering when the cohort members were 8 years old. In this study, we will look at whether and how mental health difficulties emerged in children who stuttered at 8 years as they grew into adolescents and adults. Since not all people who grow up with a stutter end up with serious mental health problems, we will also try to identify factors that are associated with positive mental health in people who stutter. We will also gather new data from the cohort members, to find out about stuttering in adulthood and its relationship to mental health. We will ask participants to complete a screen for common mental health problems and a separate measure of social anxiety, which is often elevated in people who stutter.